LARGE1 and proximal spinal muscular atrophy: To validate our proteomic findings and to further elucidate the potential of LARGE1 to serve as a (therapeutic relevant) biomarker for SMA, ELISA-based quantification of LARGE1 level was carried out in CSF samples derived from pediatric patients suffering from SMA type 1 (n = 3), type 2 (n = 4) and type 3 (n = 3) responding to therapeutic intervention as well as in 4 pediatric non-responders in addition to adult patients suffering from SMA type 3 (n = 18).